Apparatus for producing aerosol product

ABSTRACT

The aerosol product, for example a cosmetic or pharmaceutical preparation, contains an active agent, a propelling agent and a solvent; with a view to protect the environment and the users the propelling agent is comprised exclusively of, helium, neon, argon, krypton or mixtures of these gases. A percentage of at least 80% by weight of argon with respect to the total weight of the propelling agent has proved to be particularly interesting. The method consist mainly in contacting the active agent and the solvent into an autoclave, introducing a compressed noble gas in a predetermined amount and collecting the mixture obtained. The mixing process may be repeated in other autoclaves with different noble gases. The device comprises mixtures (1,2;3) for storing the active agent and the solvent connected, as well as a pressure accumulator (a) for noble gases, to an autoclave (12) on which an outlet connection (14) is fixed, above the ground. Several autoclaves (15, 18) may be provided as well as a filter having the shape of a candle (22, 10a), arranged after the last autoclave (18) and/or before the first autoclave (12 ).

TECHNICAL FIELD

The invention relates to an aerosol product consisting of an activesubstance, propellant and solvent. Furthermore, the invention concerns aprocess for the production of an aerosol product as well as an apparatusfor carrying out the process.

STATUS OF THE PRIOR ART

Aerosol products with different propellants have been known. Since thepropellants become volatile upon atomization and at the same time mayeasily reach up to open spaces of combustion, it is generally demandedof them that their combustibility be lowered.

A known example for such propellants is chlorine fluorine hydrocarbons.However, their use does not seem to be quite harmless, since there atleast exists the possibility that in the case of a continuous and largerexpulsion into the atmosphere of the earth, an attack on the ozone beltsurrounding the earth takes place which is of significance for theabsorption of UV radiation.

Also propellants free of chlorine fluorohydrocarbons have been known(cf. German OS No. 2 741 882), namely with 65 to 85% by weight of1,1,1-trichloroethane, dichloro methane or mixtures of these, 14 to 32%by weight of butane, isobutane, propane or mixtures thereof andapproximately 0.5 to 5.3% by weight of carbon dioxide.

The high portion of 1,1,1-trichloroethane for many fields of applicationis a disadvantage in that case. For one thing, when sprayed into an openflame, as it occurs regularly in the case of laboratory experiments(flame tests, etc.) or also unintentionally in practical use, thesecomponents are subject to decomposition reactions, whereby among othershydrochloric acid may develop and for another thing, it is also riskyeven without any decomposition taking place, whenever a consumer comesinto direct contact with those components, especially if he also inhalesthem along with others. This comes into consideration mainly in the caseof aerosol products in the field of pharmaceutics but also in the caseof numerous other aerosol products, since their liberation practicallyalways takes place in the immediate vicinity of the consumer.

DESCRIPTION OF THE INVENTION

This is where the invention starts. It is based on the task ofdescribing an aerosol product from which these dangers no longeremanate. Thus, the areosol product as far as its propellant isconcerned, is to be distinguished by a decrease combustibility as wellas by a neutral behavior concerning the environment, as well asconcerning the immediate health of the consumer. Furthermore, theinvention is to describe a process for the production of such an aerosolproduct as well as an aparatus to carry out the process.

The task is solved in the case of an aerosol product consisting of anactive substance, a propellant and a solvent, in a surprisingly simpleand at the same time effective manner by the fact that the propellantconsists exclusively of helium, neon, argon, krypton or mixturesthereof.

This is true both for powdered sprays, foam sprays, as well as above allwetting sprays. The number of noble gases cited depends for one thing ontheir cost and for another thing on their physical properties.

From the German Pat. No. 1 170 909 self-propellant mixtures have beenknown which as propellants contain an inert gas and a halogenatedmethane. At the same time, the inert gas consists of a mixture ofsulfuric hexafluoride and an inert, noncombustible gas, for example,also argon, helium or neon.

The German OS No. 21 31 668 concerns an anaerobic agent, especiallyadhesives in aerosol form, setting especially in the presence of oxygen.Beside the "anaerobic agent", there is an inert gas and oxygen presentin the containers under pressure. Beside its chemical functions, theoxygen at the same time also acts as a propellant. Helium, neon andargon are mentioned among others also as inert gases.

From none of the previously mentioned printed documents does the use ofnoble gases as sole propellant for aerosols become clear.

Noble gases are absolutely incombustible and thus they are superior topropellants hitherto. Furthermore, they constitute no danger for theatmosphere of the earth but they are altogether to be classified ascompatible with the environment. As is well known, they are obtained,indeed, in a purely physical way from the environmental air, so thattheir later liberation signifies no contamination or impairment of theenvironment, but merely a return to their origin.

Further advantages are that their use is probably harmless from adermatological and toxicological point of view for the human being aswell as for animals; finally, the human being inhales and exhales about20 liter of argon daily together with the respiratory air.

Noble gas has the advantage of acting without intoxicating effect,especially for aerosol products in the field of pharmaceutics. As iswell known, aerosol products which contain chloro fluoride hydrocarbonsas propellants may have an intoxicating effect. This effect is also usedby numerous labile patients for the purpose of getting intentionallyintoxicated. Quite a few patients have come thereby into a dependence onsuch aerosol products which is expressed frequently also by the factthat already corresponding medical weaning cures are made and areadvertised in newspaper advertisements.

The significance of the invention for aerosol products in the field ofpharmaceutics may be illuminated further by the fact that presentlyseveral dozens of medical preparations are sold in aerosol form in aregular drugstore, among them so-called nitro sprays (as prescribed inthe case of contraction of the coronary vessels of the heart), asthmasprays, throat and mouth sprays, for the treatment of eczemae, woundsprays and sprays for dressings of wounds, etc.

Let us also mention that noble gases probably also have a sterilizing,bacteria killing effect, which in any case is desirable.

Furthermore, noble gases have the advantage of being odorless andtherefore they are suitable particularly also as aerosol products in thefield of cosmetics.

In addition, noble gases lead to an excellent spray behavior in the caseof aerosol products. Owing to their good capacity for dissolution inliquids, sufficient quantities of propellants may easily be dissolved inliquid active substances or the solvents for active substances and afavorable adjustment of the pressure conditions may be achieved, i.e., amore or less constant operating pressure and a uniform distribution(fine atomization).

Finally, the rise in pressure by increase of temperature is low in thecase of noble gases, which additionally represents a particular safetyfactor.

Effectively, the propellant is a mixture of the above mentioned noblegases.

It is particularly advantageous whenever the propellant is a mixture ofnoble gases with a share of argon of at least 80% by weight related tothe total weight of the propellant.

For the production of an aerosol product according to the invention, theactive substance and the solvent are brought together under pressureaccording to a further proposal of the invention, are charged overheadto a pressure container and seeped in it. At the same time, a noble gascompressed overhead is introduced into the pressure tank and is added bydoses to the active substance-solvent mixture. Subsequently, the mixturethat develops is collected and is fed to a bottling plant. In this way,the aerosol product may be enriched to a sufficient degree with noblegas.

Advantageously, the active substance-solvent mixture is charged tofurther pressure tanks and processed as before. Preferably, variousnoble gases are introduced into the pressure tanks.

The apparatus according to the invention is characterized by a mixingvessel for the storage of active substance, a mixing vessel for thestorage of solvent, whereby the mixing vessels have feed lines separatedfrom one another and are provided with discharge lines which converge toa common conveying line, furthermore by a pressure tank with an inletconnection overhead to which the common conveying line is connected, afurther inlet connection overhead to which a pressure storage for noblegas is connected as well as an escape connection which is disposed at adistance from the floor of the pressure tank.

Advantageously, additional pressure tanks are provided.

In a further development of the idea of the invention, a filteringcandle has been provided behind the last pressure tank and/or in frontof the first pressure tank.

BRIEF DESCRIPTION OF THE DRAWING

The invention is to be explained further subsequently in connection withthe drawing. The only FIGURE shows an apparatus according to theinvention in a diagrammatic simplification.

According to the FIGURE, the apparatus consists of a mixing vessel 1 foran active substance and a mixing vessel 2 for another active substance,further of a mixing vessel 3 for a solvent. Separate feed lines 4, 5, 6lead to the individual mixing vessels 1, 2, 3 which always have anagitating mechanism. Discharge lines 7, 8,9 start off from the mixingvessels 1, 2, 3 which converge into a common conveying line 10. Thelatter has a filter candle 10a, a conveying pump 10b and a locking slide10c. The conveying line 10 is connected furthermore to an inletconnection 11 of a pressure vessel 12. The inlet connection 11 at thesame time is disposed overhead of the pressure vessel 12. Likewiseoverhead, an additional inlet connection 13 is disposed on the pressurevessel 12 to which a pressure tank (in this case a pressure flask) 12afor a noble gas has been connected.

At a distance from its floor, the pressure vessel has a dischargeconnection 14. Another section of the conveying line 10 is connectedthereto and leads to a further pressure vessel 15 which, in turn, hasagain a connection 16 for the arriving mixture and an inlet connection17 for the noble gas to be added by doses. Analogously, a further stepwith a pressure vessel 18 and an inlet connection 19, 20 follows. Thepressure vessels 12, 15, 18 in this case are developed as pressurefilter vessels.

The last filter container 18 is again followed by a section of theconveying line 10. An excess pressure valve 21 as well as a filtercandle 22 are inserted in the latter. The latter contains a transparentoutside housing and at the same time it makes possible a visible controlbefore the mixture obtained will reach a filling plant not shown here.As can be seen furthermore, before and behind each pressure vessel 12,15, 18, a closing slide has been provided, namely the closing slide 10calready mentioned as well as the additional closing slides 23, 24 and25. Finally, one more closing slide is attached also behind the filtercandle 22 which has been designated here by 26.

The apparatus of the invention operates as follows: The activesubstances or the solvents flow via their pertinent discharge lines 7, 8or 9 into the common conveying line 10. There, they are mixed underpressure. The active substance-solvent mixture then reaches the pressurecontainer 12 where it enters overhead and seeps. At the same timekrypton is likewise introduced overhead and added by doses to themixture.

The mixture obtained thus subsequently reaches the pressure vessel 15where an enrichment with helium takes place in a similar manner.Thereupon, that mixture reaches the pressure vessel 18 where an evengreater enrichment with argon takes place, namely with at least 80% byweight related to the total weight of the propellant. After passingthrough the filter candle 22, the aerosol product according to theinvention reaches a filling plant for bottling.

I claim:
 1. Apparatus suitable for the production of an aerosol productconsisting of active substance, propellant and solvent wherein thepropellant consists exclusively of a noble gas which is helium, neon,argon, krypton or mixtures thereof by a process comprising bringingtogether the active substance and the solvent under pressure, chargingoverhead to a pressure vessel and seeping therein, while at the sametime introducing into the pressure vessel a compressed noble gas andadding the noble gas by doses to the active substance-solvent mixtureand subsequently collecting the newly developed mixture and feeding itto a bottling plant, said apparatus comprising a mixing vessel (1, 2)for the storage of active substance, a mixing vessel (3) for the storageof solvent, whereby the mixing vessels (1, 2; 3) have feed lines (4, 5;6) separated from one another and are provided with discharge lines (7,8; 9) which converge to a common conveying line (10), furthermorecharacterized by a pressure tank (12) with an inlet connection (11)overhead, which is connected to the common conveying line (10), anadditional inlet connection (13) overhead, to which a compression tank(12a) for noble gas has been connected as well as a discharge connection(14) which is disposed at a distance from the bottom of the pressurevessel (12).
 2. Apparatus as in claim 1, characterized in thatadditional pressure vessels (15, 18) have been provided.
 3. Apparatus asin claim 1 or 2, characterized in that behind the last pressure vessel(18) and/or before the first pressure vessel (12) a filter candle (22,10a) has been provided.